25 resultados para sulfate-reducing bacteria
Resumo:
The Duck Creek Watershed, the recipient of a 2009 DNR Watershed Management Planning Grant and a focus of an upcoming City of Davenport master plan, is characterized by relatively flat grades and highly impervious areas. Plagued by issues such as high bacteria loads, stream bank erosion and flooding, solving these problems may take generations. The City of Davenport has taken a microwatershed approach to identify the significant contributors to water quality and flooding issues that affect Duck Creek, its tributaries and the surrounding landscape to make inroads into the larger issues. This project is the next phase of a multi-phased project that addresses the microwatershed that includes St Ambrose University. Work here will improve water quality within Duck Creek and address major flooding issues on campus while also reducing downstream flooding. This project will convert an existing parking lot into a green parking area by removing the hard surface and installing below ground facilities for storm water infiltration, detention, and reuse. Permeable pavement, bio swales and infiltration areas will be constructed on top of the infiltration facilities. We estimate that this project will capture and treat 1,110,000 gallons (3.5 acre feet) of storm water runoff which accounts to the runoff volume from a 10-year storm event while reducing pollutants by 30-100%.
Resumo:
Lake Morris is the larger of two lakes which serve as the municipal water supply for the City of Chariton, Iowa. As a site for fishing and boating, it also serves as a significant recreational resource for area residents. Its ability to sustain these uses has been significantly impaired by long-term and ongoing accumulation of sediment and sediment-borne nutrients from both public and private land within the watershed. This accumulation has resulted in reduced water depth, reduced water-holding capacity, reduced quality of the fishery, increased water turbidity, increased growth of undesirable algae, and increased cost of treating the water for municipal uses. Water quality projects undertaken in the past, notably the Lucas Lakes Project of the 1990s, made important progress in reducing sedimentation from privately-owned land higher in the watershed, but paid little attention to land owned by the City of Chariton immediately surrounding the lakes. A recent reassessment of gully erosion within the watershed shows serious, ongoing erosion on that City-owned land. This project proposes a two-part approach to improving the water quality in Lake Morris. First, we propose that a complement of five SolarBee water circulation devices be installed in Lake Morris to provide near-term and continuing improvements in water quality, by inhibiting cyanobacterial growth and thereby removing the need for treatment of the lakes with copper sulfate. Second, we propose the installation of erosion-control structures on primarily City-owned land surrounding the lake, to provide a major reduction in ongoing sedimentation.
Resumo:
Concrete durability may be considered as the ability to maintain serviceability over the design life without significant deterioration, and is generally a direct function of the mixture permeability. Therefore, reducing permeability will improve the potential durability of a given mixture and, in turn, improve the serviceability and longevity of the structure. Given the importance of this property, engineers often look for methods that can decrease permeability. One approach is to add chemical compounds known as integral waterproofing admixtures or permeability-reducing admixtures, which help fill and block capillary pores in the paste. Currently, there are no standard approaches to evaluate the effectiveness of permeability-reducing admixtures or to compare different products in the US. A review of manufacturers’ data sheets shows that a wide range of test methods have been used, and rarely are the same tests used on more than one product. This study investigated the fresh and hardened properties of mixtures containing commercially available hydrophilic and hydrophobic types of permeability-reducing admixtures. The aim was to develop a standard test protocol that would help owners, engineers, and specifiers compare different products and to evaluate their effects on concrete mixtures that may be exposed to hydrostatic or non-hydrostatic pressure. In this experimental program, 11 concrete mixtures were prepared with a fixed water-to-cement ratio and cement content. One plain mixture was prepared as a reference, 5 mixtures were prepared using the recommended dosage of the different permeability-reducing admixtures, and 5 mixtures were prepared using double the recommended dosage. Slump, air content, setting time, compressive and flexural strength, shrinkage, and durability indicating tests including electrical resistivity, rapid chloride penetration, air permeability, permeable voids, and sorptivity tests were conducted at various ages. The data are presented and recommendations for a testing protocol are provided.
Resumo:
Effective winter maintenance makes use of freezing-point-depressant chemicals (also known as ice-control products) to prevent the formation of the bond between snow and ice and the highway pavement. In performing such winter maintenance, the selection of appropriate ice-control products for the bond prevention task involves consideration of a number of factors, as indicated in Nixon and Williams (2001). The factors are in essence performance measurements of the ice-control products, and as such can be easily incorporated into a specification document to allow for selection of the best ice-control products for a given agency to use in its winter maintenance activities. Once performance measures for de-icing or anti-icing chemicals have been specified, this allows the creation of a quality control program for the acceptance of those chemicals. This study presents a series of performance measurement tests for ice-control products, and discusses the role that they can play in such a quality control program. Some tests are simple and rapid enough that they can be performed on every load of icecontrol products received, while for others, a sampling technique must be used. An appropriate sampling technique is presented. Further, each test is categorized as to whether it should be applied to every load of ice-control products or on a sampling basis. The study includes a detailed literature review that considers the performance of ice-control products in three areas: temperature related performance, product consistency, and negative side effects. The negative side effects are further broken down into three areas, namely operational side effects (such as chemical slipperiness), environmental side effects, and infrastructural side effects (such as corrosion of vehicles and damage to concrete). The review indicated that in the area of side effects the field performance of ice-control products is currently so difficult to model in the laboratory that no particular specification tests can be recommended at this time. A study of the impact of ice-control products on concrete was performed by Professor Wang of Iowa State University as a sub-contract to this study, and has been presented to the Iowa Highway Research Board prior to this report.
Resumo:
Bear Creek is an impaired warm water fishery designated as class B(LR) by the Iowa DNR and is on 303 impaired waters list for fish kills and ammonia. Bear Creek is located in eastern Delaware County. This project is designed to improve the water quality of Bear Creek by educating the landowners, operators and watershed community about the importance of this water resource. The goal of the Bear Creek Watershed Project is to improve the water quality of Bear Creek by reducing the amounts of ammoniated manure discharge, fecal coliform bacteria, sediment, nitrogen, and phosphorous. The Bear Creek Watershed Project has been a watershed project since July 2004, first as a Demo project FY 2004-2005 and then full time WSPF/319 project FY06-09. Fish kills have not occurred in 2008-2009. Sediment delivery has decreased in the Bear Creek Watershed by 5,328 tons per year. The objectives of this watershed project will be to improve Livestock Waste Storage, to improve Livestock Waste Usage, to decrease Sediment Losses, and to improve Education & Area Outreach. This project will install 2 manure storage structures (EQIP/project funded), 19 ac of CRP waterways, 12 ac of project waterways, 17 ac of CRP filter strips along stream, 12 water and sediment control basins, 18,000 ft of terraces, 350 ac of new notill planting, and 3,700 ft of streambank protection.
Resumo:
Clear Lake, Iowa's third largest natural lake, is a premier natural resource and popular recreational destination in north central Iowa. Despite the lake's already strong recreational use, water quality concerns have not allowed the lake to reach its full potential. Clear Lake is listed on Iowa's 2004 303(d) Impaired Waters List due to excessive levels of phosphorus, bacteria, and turbidity. Urban storm water runoff from the 8,600 acre watershed is a significant contributor to Clear Lake's impairment. Local communities have been working towards the goal of making improvements at all 30 storm water outlets that have a drainage area of five acres or more and have a cost effective solution. Many improvements have already been made, and now there are only seven storm water outlet sites remaining that still need protection in order to meet the goal. The storm water improvements have been very effective in reducing contaminants in urban runoff, achieving reduction levels in the 50-80% range. The proposed Clear Lake Storm Water Improvement Project will address the remaining seven outlet sites and take place over three years. The first year will consist of performing engineering and design of storm water best management practices (BMPs) at the seven outlet sites to determine if a cost effective solution exists for each. Years two and three will consist of installing two storm water improvements each year to implement the most cost effective BMPs at a minimum of four of the seven sites. The grant request addresses one of the main priorities of the Iowa Watershed Improvement Grant: storm water runoff.
Resumo:
Dry Run Creek Watershed was designated an impaired waterbody by DNR in 2002, following an assessment of the biota in the stream by DNR Biologist, Tom Wilton. Subsequent studies by IOWATER Snapshot effort in 2003, found e-coli bacteria concentrations and high nitrate readings in excess of the State of Iowa limits for recreational streams. The Dry Run Creek Watershed Improvement Project is comprised of five major components. Three components will feature demonstrations of structural best management practices (BMPs) to protect water quality in Dry Run Creek. The fourth is an educational workshop to "kick-off" the initiative and background the stakeholders of the watershed in new stormwater management strategies for water quality protection. The fifth is a monitoring program that will provide data on the effectiveness of the practices to be demonstrated. Measurable outcomes from these projects include monitoring to document the effectiveness of infiltration based BMPs to reduce pollutant loading in urban stormwater runoff and reducing the volume of stormwater discharged directly into Dry Run Creek via storm sewer flows. Understanding of and social acceptance of new stormwater strategies and practices will also be monitored by surveys of watershed stakeholders and compared to findings of a survey done before the start of the project.
Resumo:
An overall effort has been initiated to improve the quality of the Yellow River in Northeast Iowa by reducing the amount of sediment and bacteria entering the stream. Funding for this project will be utilized to improve stream quality to the level of fully supporting game fish such as brown, rainbow and brook trout, walleye, northern pike and smallmouth bass. The Yellow River has the potential to be one of the top trout streams, not only in Iowa, but in the entire Upper Midwest. This project will greatly enhance recreational activities such as fishing, canoeing and inner tubing and will greatly increase tourism dollars to the state. The project will specifically address two sources of impairment: stream bank erosion and coliform bacteria from both livestock and inadequate human septic systems.
Resumo:
Clear Lake, Iowa's third largest natural lake, is located in Cerro Gordo County in north-central Iowa. The lake is a premier natural resource and popular recreational destination in north central Iowa, providing more than $40 million dollars annually to the local economy. Despite the lake's already strong recreational use, water quality concerns have not allowed the lake to reach its full recreational potential. Clear Lake is listed on Iowa's 2004 303(d) Impaired Waters List due to excessive levels of phosphorus, bacteria, and turbidity. Urban storm water runoff from the 8,600 acre watershed is a significant contributor to Clear Lake's impairment. There are over 68 storm water outlet points in the Clear Lake watershed that allow untreated urban runoff to empty directly into Clear Lake. Local governments have been very active in installing storm water Best Management Practices (BMPs) at as many of the outlets that current funding allows. To date, 11 of the 68 sites (16%) have been protected. These improvements have been very effective in reducing contaminants in the storm water runoff, but the remaining outlets still need protection. The first phase of this grant request is for an investigation of 10 storm water outlet sites to determine the most cost effective BMP for each site. The second phase of the grant request is to implement the BMPs deemed most cost effective at 5 of the 10 sites investigated. The grant request addresses one of the main priorities of the Iowa Watershed Improvement Grant: storm water runoff.
Resumo:
Clear Lake, Iowa's third largest natural lake, is a premier natural resource and popular recreational destination in north central Iowa. Despite the lake's already strong recreational use, water quality concerns have not allowed the lake to reach its full potential. Clear Lake is listed on Iowa's Draft 2010 303(d) Impaired Waters List for algae, bacteria, and turbidity. Many restoration practices have been implemented to treat the algae and turbidity impairment, but few practices have been installed to treat bacteria. Reducing beach bacteria levels is a priority of the lake restoration partners. Federal, State, and local partners have invested more than $20 million in lake and watershed restoration efforts to improve water clarity and quality. These partners have a strong desire to ensure high bacteria levels at public swim beaches do not undermine the other water quality improvements. Recent bacteria source tracking completed by the State Hygienic Laboratory indicates that Canada Geese are a major contributor of bacteria loading to the Clear Lake swim beaches. Other potential sources include unpermitted septic systems in the watershed. The grant request proposes to reduce bacteria levels at Clear Lake's three public swim beaches by utilizing beach cleaner machines to remove goose waste, installing goose deterrents at the swim beaches, and continuing a septic system update grant program. These practices began to be implemented in 2011 and recent bacteria samples in 2012 are showing they can be effective if the effort is continued.